Although the Garda has not ruled out burglary as a motive, investigators believe the attack has the hallmark of a pre-planned anti-Islam attack.

“The taking of the security equipment suggests an effort to hide their tracks. It indicates a level of planning and sophistication,” said a garda.

A Garda forensic team spent Monday examining the mosque and a team of detectives have been assigned to the case.

Online extremism

The Garda Racial, Intercultural and Diversity Office (Grido), which monitors the spread of extremism online, will also assist the investigation.

Monday’s incident was the second attack on the Maryam Mosque since it opened in 2014.

Members of Grido, which has recently been restructured by Garda management, contacted Imam Noonan on Monday morning.

Both of the groups mentioned to Imam Noonan have been known to Grido for some time as some of the main purveyors of online anti-immigrant and anti-Islam sentiment in Ireland.

However, both organisations are believed to have very small memberships, with supporters often hiding behind anonymous online identities.

“There are certain groups out there who like to stir up racial hatred and we have to be watching that all the time,” Insp David McInerney of Grido told The Irish Times earlier this year.

“These are certain individuals who come up time and time again. We know people who are at this all the time. They move on, they change the name of the site and then they start again.”

The Catholic Bishop of Galway Brendan Kelly was among those to condemn the attack, saying he was “dismayed and shocked at the wilful and malicious assault” on the mosque.

“An attack on a place of worship is an assault on God and an assault on all people of faith. We stand in solidarity with our Muslim neighbours. With them, we reject violence, we reject division and we reject hate,” the bishop said.

A number of groups including the Galway Anti Racism Network planned to organise a gathering at the mosque on Monday night in solidarity with the Muslim community there.